High-power battery modules using multiple battery cells are being developed. The battery cells may include, e.g., a non-aqueous electrolyte with high energy density. A large-capacity battery module may be configured by connecting a plurality of battery cells in series. For example, the battery modules may be used in driving motors of devices requiring high power, e.g., electric vehicles and the like.
As devices using battery modules have various external appearances, shapes of the battery modules may be varied to correspond with the external appearances. Further, the demand for light and small-sized battery modules has increased. In addition, since safety is a concern with respect to battery modules, studies on the structures of the battery modules have been conducted in many fields so as to satisfy these requirements.